HDMI input no signal

I have a Samsung UN40HU6950 4K Smart TV. The HDMI inputs 1, 2 and 4 which support 4:2:2 YCbCr color mode at 3840x2160 60hz intermittently work. HDMI input 3 only supports 4:2:0 YCbCr color mode at 3840x2160 60hz always works. If I change the signal source from any of the 4:2:2 inputs to another input, all 4:2:2 inputs will stop working until the TV is turned off and on again via the remote. Occasionally turning the TV off and back on again wont work and the TV will have to have the power cable removed and plugged back in again before the 4:2:2 inputs will start working. I'm using this TV with two different PCs, each utilizing Nvidia GTX 980 GPUs, and each has their own HDMI 2 cable so I can safely rule out the cable or signal source as being the problem.

Unfortunately my unit is out of warranty. Is there anything which can be done about this? Such as replacing a board or a component level repair? I'm comfortable doing it myself and soldering. Are there service manuals or block diagrams available?